Kohn V G, Smirnova I A
National Research Centre `Kurchatov Institute', 123182 Moscow, Russian Federation.
Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow district, Russian Federation.
Acta Crystallogr A Found Adv. 2015 Sep;71(Pt 5):519-25. doi: 10.1107/S2053273315012176. Epub 2015 Jul 9.
The results of theoretical and experimental study are presented for the question of how the X-ray multiple diffraction in a silicon single crystal influences the interference fringes of section topography for the 400 reflection in the Laue case. Two different cases of multiple diffraction are discovered for zero and very small values of the azimuthal angle for the sample in the form of a plate with the surface normal to the 001 direction. The cases are seen on the same topogram without rotation of the crystal. Accurate computer simulations of the section topogram for the case of X-ray multiple diffraction are performed for the first time. It is shown that the structure of interference fringes on the section topogram in the region of multiple diffraction becomes more complicated. It has a very sharp dependence on the azimuthal angle. The experiment is carried out using a laboratory source under conditions of low resolution over the azimuthal angle. Nevertheless, the characteristic inclination of the interference fringes on the tails of the multiple diffraction region is easily seen. This phenomenon corresponds completely to the computer simulations.
针对硅单晶中的X射线多重衍射如何影响劳厄情况下400反射的截面形貌干涉条纹这一问题，给出了理论和实验研究结果。对于表面垂直于001方向的平板状样品，在方位角为零和非常小的值时，发现了两种不同的多重衍射情况。在不旋转晶体的情况下，在同一张形貌图上可以看到这些情况。首次对X射线多重衍射情况下的截面形貌图进行了精确的计算机模拟。结果表明，多重衍射区域的截面形貌图上干涉条纹的结构变得更加复杂。它对方位角有非常强烈的依赖性。实验是在方位角分辨率较低的条件下使用实验室光源进行的。然而，在多重衍射区域尾部干涉条纹的特征倾斜很容易看到。这一现象与计算机模拟完全相符。
